In a printing control apparatus having a copy function, image data read by a reading unit is printed by a printing unit. As a method for reading an image on a document used at this time, a feed reading method is known. In the feed reading method, a document is set on a document setting unit, and an image on the document is read at a fixed position of an optical system while the document is being conveyed by a document conveying unit (ADE: Auto Document Feeder).
In addition, a technique for reducing time (First Copy Out Time: FCOT) taken until a first sheet is output when an image on a document is read and the read image is printed on a sheet is known. Printing on the first sheet is usually performed after reading of image data for one page ends. On the other hand, in PTL 1, reading of image data performed by a reading unit and transfer of the image data to a printing unit are performed as parallel processes, and printing starts before reading of image data for one page ends, in order to reduce the FCOT. In addition, in PTL 2, a printing control apparatus that determines, after a start button is pressed, whether job settings correspond to an FCOT mode is described. This printing control apparatus determines that the job settings correspond to the FCOT mode if parameters set for a job are certain parameters, such as the size of a document being A4, a reading scaling factor being 100%, a specified. tray being a tray closest to a printing unit, and the size of a sheet being A4, and performs control for reducing the FCOT.
If the FCOT is to be reduced by starting printing without until reading of image data for one page ends, parameters relating to a reading process and a printing process need to be determined before a copy job starts. A reading size of a document, for example, needs to be determined as one of the parameters.
In addition, in a copying process, an operation for starting printing without waiting until reading of image data for one page ends might not be possible. If a function such as “scaling”, in which printing is performed after the size of an image is changed, or “page integration”, in which a plurality of pages are laid out on a surface of a sheet, is set, for example, processing on an image needs to be performed after image data for one page is read. Printing can therefore start only after the reading of the image data ends.
In addition, the following two types of method are known as a method for automatically detecting the size (document length and document width) of a document to be read by the ADF. A first method is a method in which the size of a document is detected by a sensor provided on the document setting unit. In addition, a second method is a method in which the size of a document is detected by a sensor provided along a conveying path.
If the size of a document is detected by the sensor on the document setting unit, the size of the document can be detected before reading starts, and the FCOT can be reduced using the above-described method. If the size of a document is detected on the document setting unit, however, erroneous detection might occur.
If the size of a document is detected on the document setting unit, a method for detecting the size of a sheet on the basis of whether a protrusion on the document setting unit is pressed by the sheet, for example, is used. In this method, however, the size of a document is erroneously detected if a rounded document (a curled document in the following description) or a document with a fold (a folded document in the following description) is set with part of the document not in place. In this case, for example, a curled document of A3 size is erroneously detected as having A4 size, and printing is performed with part of the actual document missing although the document of A3 size is copied.
On the other hand, if the method in which the size of a document is detected in the conveying path is used, the size of the document can be correctly detected even if the above-mentioned curled document or folded document is read. Since the size of the document is not detected before a starting of reading, however, the FCOT cannot be reduced using the above-described method.
Aspects of the present invention are established in view of the above and provide a mechanism for dynamically selecting a method for detecting the size of a document in accordance with conditions.